Process of producing blue sulfur dye.



ADOLF KERTESZ, OF FRANKFORT-ON-THE-MAIN, GERMANY, ASSIGNOR TO LEOPOLDGASS'ELLAK 00., OF SAME PLACE.

PROCESS OF PRODUCING BLUE SULFUR DYE.

$EEGIFICATION forming part of Letters Patent N 0. 678,884, dated July23, 1901.

Application filed July 15, 1899- To aZZ whmn it may concern:

Be it known that I, Anonn KERIESZ, a citizen of Prussia, and a residentof Frankforton-the-Main, in the Province of Hesse-Nassau and Empire ofGermany, have invented certain new and useful Improvements in ProducingOxidation Dyestuffs on the Fiber, of which the following is aspecification.

The object of this invention is to convert blacks produced by dyeingwith the hereinafter-mentioned dyestuffs into blues by treatment on thefiber in accordance with the hereinafter-described process.

Under the denomination of immedial blac Vida-l black, kyrogene blue,&c., dyestuffs have been brought on the market which are obtained byheating various primary substances with sulfur and sulfids. All thesedyestuffs have the property of dissolving easily in water in thepresence of sulfid of sodium and to dye directly the vegetable fiber insuch a solution. The said dyestuffs have already been subjected tooxidation processes on the fiber. For instance, the greenish shade ofvidal black has been changed into a black by the action of bichromatesand immedial black into a blue by means of peroxids. The oxygen of theair also reacts on vidal black, though but slowly, as its direct greendyeings when exposed to the air are turned into a pretty intense black.I have, however, found that the oxygen of the air has quite a diiferenteffect in the presence of steam of high tension or overheated. ThenVidal black is changed into a greenish blue, immedial black into areddish dark blue, kyrogene blue into a black blue, &'c. Thisobservation is of great technical importance, as the application of thisprocess is exceedingly simple and the resulting colors are of a hithertounsurpassed fastness.

The operation is executed in an apparatus,

Serial No. 723,990. specimens.)

the shape of which depends on the material to be dyed, (loose cotton,yarn, cops, &o.,) constructed on the principle that the goods aretreated simultaneously with air and steam at temperatures of more than100 centigrade. For the success of the reaction it is necessary that thefiber shows alkaline reactions. As the dyeing process is carried out ina bath containing sulfid of sodium, which possesses strong alkalinereaction, it is generally sufficient to treat the material directlywithout Washing or drying it. If this is not possible, the requisitealkaline reaction may be produced by introducing some ammonia-gas.

The term air as hereinafter usedin my claims is intended to includeatmospheric air or an equivalent supply of oxygen.

Having thus described my invention and in what manner the same can beperformed,what I claim as new, and desire to secure by Letters Patent,is

1. The process of producing blue dyes by treating with a mixture of airand steam at a temperature of over 100 Centigrade, in the presence of analkali, fiber previously dyed with the sulfur dyes obtained by treatingpri mary substances with sulfur and sulfids, as and for the purposehereinbefore set forth.

2. The process of producing blue dyes by treating with a mixture of airand steam, in the presence of an alkali, fiber previously dyed with thesulfur dyes obtained by treating primary substances with sulfur andsulfids, as and for the purpose hereinbefore set forth.

Signed at Frankfort-on-the-Main, in the Province of Hesse-Nassau andEmpire of Germany, this 22d day of June, A. D. 1899.

, ADOLF KERTESZ.

Witnesses:

JEAN GRUND, SIMON W. HANAUER.

